Hydrogen peroxide (H2O2) is a highly effective oxidizer. Its effectiveness generally increases at increasing concentrations. However, hydrogen peroxide solutions also become increasingly unstable at higher concentrations. For industrial applications, aqueous hydrogen peroxide solutions are generally stored at concentrations of 50% or less by volume. Although hydrogen peroxide solutions may be safely stored at higher concentrations, storage conditions become increasingly critical.
Many industrial applications demand concentrations above 50% by volume. Although generally unsuitable for industrial storage, concentrations of approximately 80% by volume may be attained by heating the solution to 140° C. However, the rate of decomposition of the aqueous solution increases by a factor of approximately 2.3 for each 10° C. increase in temperature. Additionally, at temperatures corresponding to the boiling point of a hydrogen peroxide solution having a concentration of approximately 72% by volume, the vapor pressure of the hydrogen peroxide produces an explosive mixture.
For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative methods and apparatus for concentrating hydrogen peroxide solutions at reduced risk of decomposition and hazard.